The present invention relates to a dental device for the manufacture of models and particularly a device having means to facilitate the removal and accurate replacement of all or part of the molded dies from the device.
Numerous methods and designs already exist for molding models i.e. making casts of the upper and lower dental arches to restore or replace teeth. The present invention provides a ready means of removing a molded model or portion thereof from a recessed tray. The device further provides a method of model fabrication and die location as well as articulation simultaneously within a single mechanism. Presently, there are problems with existing devices in removing the molds and working with the individual teeth. These drawbacks have been eliminated in the present invention where parallel ridges are included along the internal wall surfaces of the trays and an insert with projecting upper and lower ends is mounted within the trays. The element includes alternately spaced lower end portions which project through corresponding apertures in the base of the trays in order to facilitate removal of the molded model by pushing on the projected ends. The model can also be partitioned to permit working on single dies which can be accurately replaced in the original mold.
The prior art includes U.S. Pat. No. 4,103,424 to Benjamin et al, which describes the use of the transparent plastic material such as high impact polystyrene for the manufacture of disposable dental articulators. Other individual features or elements of the invention are shown in separate prior art applications such as U.S. Pat. No. 2,092,575 which illustrates the use of an adjustable stop pin for a dental articulator device and a retention or hinge pin for joining the upper and lower halves of the articulator. Finally, U.S. Pat. No. 3,495,33 to Kuhn discloses the use of retention ridges in a dental die former.
While the above patents appear to represent the most pertinent prior art without affecting the patentability of the invention, other patents of general interest do exist and may be pertinent to some degree such as U.S. Pat. No. 2,786,272 to Lindley; U.S. Pat. No. 3,577,640 to Lee; and U.S. Pat. No. 3,908,271 to Derda. Roeser U.S. Pat. No. 2,619,725 on a dental tray is also of interest as well as the additional Lindley U.S. Pat. No. 2,700,219.